D. The characters are real people.
A literary nonfiction has to do with the narration of real events as they occur and how they affect the life of people.
With this in mind, we can see that from the list of choices, option D is the best description of literary nonfiction.
Furthermore, we can see that some examples of literary non fiction includes:
Personal journals
Diaries
Memoirs, etc.
The correct answer is option D.